Spatially interpolated non-smoke and smoke PM2.5 concentrations for the US from 2006-2024

Seasonal-mean concentrations of particulate matter with diameters smaller than 2.5 μm (PM2.5) have been decreasing across the United States (US) for several decades, with large reductions in spring and summer in the eastern US. In contrast, summertime-mean PM2.5 in the western US has not significantly decreased. Wildfires, a large source of summertime PM2.5 in the western US, have been increasing in frequency and burned area in recent decades. Increases in extreme PM2.5 events attributable to wildland fires have been observed in wildfire-prone regions, but it is unclear how these increases impact trends in seasonal-mean PM2.5. Using two distinct methods, (1) interpolated surface observations combined with satellite-based smoke plume estimates and (2) the GEOS-Chem chemical transport model (CTM), we identify recent trends (2006–2016) in summer smoke, nonsmoke, and total PM2.5 across the US. We observe significant decreases in nonsmoke influenced PM2.5 in the west..., , , # Spatially interpolated non-smoke and smoke PM2.5 concentrations for the US from 2006-2024

[https://doi.org/10.5061/dryad.k0p2ngfhv](https://doi.org/10.5061/dryad.k0p2ngfhv)

## Description of the data and file structure

**We estimated daily smoke and non-smoke PM2.5 across the contiguous US (CONUS) for 2006-2023 using Environmental Protection Agency (EPA) ground monitors and NOAA Hazard Mapping System (HMS) smoke polygons.**

The daily PM2.5 data from EPA ground monitors are interpolated to ~15 km resolution to create a total PM2.5 estimate. The HMS smoke polygons are then used to identify locations where there is likely smoke somewhere in the atmospheric column. The seasonal mean or median background is calculated using pixels within the season where an HMS (dense, medium, or light) smoke polygon is not located. The seasonal background can then be subtracted from the total PM2.5 to estimate smoke PM2.5.

In recent years, an active fire season has resulted in some regions having HMS..., , **Changes after Mar 21, 2025:** 

The dataset was updated to include 2024. The corresponding files were uploaded.